1. Field of the Invention
The present invention relates to a vehicle steering system.
2. Description of the Related Art
As disclosed by JP 2006-240398 A, in a steer-by-wire vehicle steering system, when the system is in normal operation, the system operates in SBW (Steer By Wire) mode in which the vehicle is steered by steer-by-wire. On the other hand, when a defect has occurred on the system, the system operates in EPS (Electronic Power Steering) mode in which assist force on steering is generated by a reaction force motor or a steering motor.